Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=false, destructiveHint=false, openWorldHint=false and idempotentHint=false, so the safety profile is covered. The description usefully adds that the list is implicitly owned by the signed-in person (no owner parameter) and that the date drives a countdown, but it never states what happens on duplicate names, which matters given idempotentHint=false, nor what the call returns.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences: the core action and scope come first, then the follow-on call. The occasion examples earn their place by clarifying the name parameter, and there is no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple three-parameter creation tool with a single required field and annotations covering the safety profile, the description is close to sufficient. A minor gap is that it never indicates whether the new list's identifier is returned, which an agent would need in order to chain into add_person.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 67%, so the schema documents date and make_default reasonably well. The description adds real value only for `name`, via the concrete occasion examples ("Christmas 2027", "Mom's birthday") that hint at the expected format; it says nothing about make_default switching the default list, which is a user-visible side effect.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ("Creates a new gift list") plus the scope ("for the signed-in person") and illustrates the occasion field with concrete examples. It stops short of distinguishing this from the sibling create_wishlist / create_wishlist_group tools, so an agent cannot fully rule out the alternatives from the text alone.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives clear context (creating a list tied to an occasion such as Christmas or a birthday) and routes the agent forward with "Add people to it with add_person." It offers no exclusions or when-not-to-use guidance, and does not explain how to choose between this and other create_* siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.